The sharp escalation in the number of slayings over the past month has alarmed animal campaigners and police, who issued a warning at the weekend urging all cat owners to keep their pets inside at night.

Even if caught, the RSPCA cannot take direct action against the twisted killer because it can only prosecute for cruelty to animals.

The killings do not qualify because they are carried out quickly.

Dressed in dark clothing and carrying a rucksack containing a torch, knives and trapping equipment, the killer has regularly struck twice in one night and in September killed three times in a day, in North West London, Milton Keynes and Northampton.

Ex-cop Mick is convinced the killer comes from the Addiscombe area of Croydon

These included Dalmally Road, where four-year-old ragdoll cat Ukiyo was found cut into pieces two years ago.

Mr Neville said: “There is someone behind one of the doors of these suburban terraced streets hiding a wicked secret.

“This area seems to be the epicentre of his killing operations. It is where he began and where he still feels at home.

“The fact he has struck on a Sunday night in the Croydon area also indicates he is local and probably on a day off from work.

The notorious Croydon cat killer 'may be keeping heads and tails as trophies'

“Jack the Ripper struck at weekends and bank holidays.

“These roads are quiet, there is very little traffic and no CCTV. It is perfect for him.

“I believe he has been observing and carefully planning his killings from one of the houses in this area.”

The Met is leading a joint investigation, codenamed Operation Takahe, to find the killer, with the help of the RSPCA and a local animal rescue group. SNARL — South Norwood Animal Rescue and Liberty — was the first to investigate the wave of killings after seeing a Facebook post from a vet about cat mutilations.

SNARL are raising funds for veterinary post-mortem examinations to be carried out on the animals

Boudica recalled: “Her head and tail were missing. We agreed an animal could not have been responsible.

"A vet concluded she was killed by a blunt instrument then cut up by a human. It was surgical and precise and done with a knife.”

The couple are consulted by police forces around the country when the bodies of animals are found.

Tony then accompanies officers to the crime scenes.

'Taking his revenge for abuse'

THE cat killer was likely to have been violently or sexually abused as a child, and is probably known to authorities, writes MIKE SULLIVAN.

That is according to former Scotland Yard detective Mick Neville, who said: “A US study found that children exposed to domestic violence were three times more likely to be cruel to animals.

"Sexually abused children are five times more likely to hurt animals.

“He may be taking out his ‘revenge’ on cats and other animals to make up for the abuse he suffered.

“It is quite possible that the suspect began abusing animals in his childhood or youth.

“Teachers and youth workers in the Croydon area should be consulted.”

Experts have pointed to a terrifying trait of serial killers starting out by abusing animals before going on to take human lives.

Moors murderer Ian Brady, whose five victims in the Sixties were children, abused dogs, cats and rabbits as a kid.

American killer Ted Bundy confessed to the murders of 36 girls and young women in the Seventies, and is also believed to have tortured animals as a child.

Mick added that if the cat killer was in a relationship, he was likely to be violent towards his partner, and that police would probably be considering known domestic abusers around Croydon as suspects.

He said: “Research shows that 75 per cent of battered women have seen pets deliberately hurt by partners in front of their children.

“In the home, he may abuse his own family’s pet to control his partner and any children.”

The RSPCA has been analysing historical crime files on animal attackers.

Mike added: “Someone must have a suspicion about who it is. If it is a battered partner they will probably be too scared to come forward.

“However, this has been going on for a long time. Something in the first place triggered him off.

"He will be hiding in plain sight and it is just a matter of time before someone realises.

“It is a perfectly solvable case.”

The cat killer has been seen from a distance during sprees in Orpington, Kent, and Caterham, Surrey.

He is described as a white male, in his forties, with short brown hair and a pock-marked face who was dressed in dark clothing and carrying a rucksack, torch or headlamp.

A £10,000 reward is being offered by charities to help catch the killer

Police are believed to have a list of potential suspects and, with the RSPCA unable to prosecute for cruelty, are hoping to bring a charge of aggravated criminal damage, which is punishable by up to 14 years’ jail.

Tony said: “People need to understand the horror of someone who has opened their bedroom curtains in the morning, looked down and seen their beautiful cat without its head or tail.